President Kennedy is visited by Soviet Foreign Minister Andrei Gromyko, who asserts that Soviet aid to Cuba is purely defensive and does not represent a threat to the United States. Kennedy, without revealing what he knows of the existence of the missiles, reads to Gromyko his public warning of September 4 that the "gravest consequences" would follow if significant Soviet offensive weapons were introduced into Cuba.

President Kennedy meets with Minister of Foreign Affairs of the Soviet Union Andrei Gromyko in the Oval Office. The President does not reveal that he is now aware of the missile build-up.

By October 18, the president and his advisers weighed only two options: blockade or invasion.